Hydrogenation with a y type zeolite-arsenic catalyst

ABSTRACT

Hydrogenation of a mineral oil containing aromatic hydrocarbons by use of a hydrogenation catalyst comprised of a Y-zeolite containing arsenic.

United States Patent Seitzer 1 Mar. 27, 1973 [54] HYDROGENATION WITH A Y TYPE [56] References Cited ZEOLITE-ARSENIC CATALYST UNITED STATES PATENTS [75] Inventor: Walter H. Seltzer, West Chester, Pa.

3,140,253 7/l964 Plank et a! ..2O8/143 [73] Asslgnee: Sun Research and Development Co., 3,197,398 7/1965 Young ..208/ 143 Philadelphia, Pa. 3,248,316 4/1966 Barger et al. ..208Il l1 [22] Filed: 1971 Primary Examiner-Herbert Levine 21 Appl, 133 750 Attorney-George L. Church, Donald R. Johnson,

Wilmer F. McCorquodale, Jr. and Paul Lipsitz [52] U.S. Cl ..208/143, 208/254 H, 208/DIG. 2, 57 ABSTRACT Hydrogenatlon of a m1neral 011 contammg aromatlc [51] Int. Cl. ..Cl0g 23/02 h drocarbons b use of a h dro enation cam] St [58] Field of Search.....208/143, 111, DIG. 2, 254 n; y y y g y prised of a Y-zeolite containing arsenic.

3 Claims, No Drawings HYDROGENATION WITH A Y TYPE ZEOLITE- ARSENIC CATALYST [t is known in the art to effect hydrogenation of mineral oils containing aromatic hydrocarbons so as to obtain products of lower boiling range; e.g., materials in the gasoline range. For example, U. S. Pat. No. 3,197,398 (D. A. Young, issued July 27, 1965) discloses such a process where the catalyst used is a molecular sieve of the X, Y, or L crystal type containing a Group VIII metal. It is also known to the skilled art worker in the field of catalystic hydrogenation that arsenic acts as a poison or inhibitor of a large number of catalysts in numerous types of reactions. In the text Catalysis by Berkman, Morrell, and Egloff (Reinhold, l940) it is reported at page 393 that arsenious oxide due to its reduction to arsine, is a strong poison for catalytic hydrogenation with platinum as catalyst.

It has now unexpectedly been found, however, that hydrocarbons such as mineral oil containing aromatic components are effectively hydrogenated to a hydrocarbon composition of less aromaticity and greater saturation by use of a hydrogenation catalyst consisting of a Y type zeolite molecular sieve which contains arsenic or a combination of arsenic with iron, cobalt, or zinc.

The catalysts of this invention may be employed for the hydrogenation of substantially any mineral oil fraction boiling above the conventional gasoline range, i.e., above about 300F., and usually above about 400F., and having an end-boiling-point up to about 1,000F., but preferably not greater than about 850F. These feedstocks may be sulfur-free, or they may contain up to about 5 percent by weight of sulfur, in the form of organic sulfur compounds. They may also contain organic nitrogen compounds. Specific feedstocks contemplated comprise straight-run gas oils and heavy naphthas, coker distillate gas oils and heavy naphthas, deasphalted crude oils, cycle oils derived from catalytic or thermal cracking operations and the like. These feedstocks may be derived from petroleum crude oils, shale oils, tar sand oils, coal hydrogenation products and the like. Specifically, it is preferred to employ oils having an end-boiling-point between about 400 and 650F., an API gravity between about 30 and 35, and containing at least about percent by volume of aromatic hydrocarbons.

Hydrogenation conditions to be employed in the process of the invention will be within the following ranges:

Operative Preferred Temperature, C. 200-460 260-400 Pressure, p.s.i.g. 400-5,000 750-2,000 H./oil ratio, s.c.f./B l,000-l5,000 LOGO-10,000

' ammonium chloride and then washing with water until chloride ions are no longer present. The ammonium form of the molecular sieve is then treated with an aqueous solution of arsenic pentoxide at elevated temperature (about -95C.) for several hours and then filtered and dried at about 150C. During this treatment arsenic is absorbed on the zeolite surface. The

catalyst is further heated at about 400C. for about 1 to 1 3 hours to effect activation. I

The amount of arsenic on the molecular sieve may vary from about 1 percent to about 15 percent by weight, preferably about 5 to 10 percent. The amount of arsenic on the support is readily controlled by the amount of arsenic pentoxide in the aqueous treating medium and by the time of treatment, which techniques are known in the art.

As indicated above, the arsenic containing molecular sieve catalyst may also have present iron, cobalt, or zinc. The arsenic and iron combination results in a more active hydrogenation catalyst. The combination of arsenic with cobalt or zinc, although not more active for hydrogenation than arsenic alone, is desirable for use with high nitrogen containing feeds as these combinations significantly lower the nitrogen content in the hydrogenated products. It is of interest to note that combinations of arsenic with certain other metals are detrimental to hydrogenation. For example, arsenic in combination with molybdenum, a known promoter for hydrogenation catalysts, shows significantly less hydrogenation activity than molybdenum alone. Thus, the known high specificity of catalytic action is clearly in evidence. When using combinations of arsenic with cobalt, zinc, or iron the amounts of these metals present on the catalyst will be from about 1 percent to about 15 percent, preferably, 3 to 7 percent. Like the arsenic, they are put on the catalyst from an aqueous solution of their water soluble salts.

In order to further illustrate the invention the following examples are given.

EXAMPLE 1 A commercial Y zeolite (LindeSK-40) was treated three times with an aqueous solution of ammonium chloride at 80C. for one-half hour and then washed with water until free of chloride. Then, 150 grams of the ammonium zeolite was then stirred in a solution of 25g. of arsenic pentoxide in 450 ml. of water at C. for 16 hours. The solids were filtered off and heated in a rotating furnace at about 400C. for 2 hours.

One part by weight of catalyst and 5 parts of a slurry oil, (a petroleum fraction boiling at 550 to 950F. and containing 1.3 percent sulfur) were placed in a stirred batch reactor, heated to 400C. and pressured to 2,500 p.s.i.g. with hydrogen. A drop in hydrogen pressure to 1,300 p.s.i.g. indicated that hydrogenation had occurred. The product oil contained 14 percent by volume of lighter boiling distillate (below 430F.)

EXAMPLE 2 A catalyst was prepared as in Example 1 except that iron was incorporated with the arsenic by exchanging 50 grams of the arsenic-ammonium Y zeolite with a solution of 40 grams of ferrous chloride in 300 ml. water at 90C. for 4 hours, filtering, drying, and heat treated as in Example 1. The slurry oil was similarly hydrogenated at 400C. and the amount of hydrogen absorbed was equivalent to 3,600 p.s.i.g. Over 20 percent by volume of the product distilled below 430F.

When the hydrogenation was repeated using a similar catalyst, but free of arsenic, hydrogen absorption was only an amou t equivalent to 1,700 p.s.i.g.

EXAMPLE 3 Example 2 was repeated at 430C., but using an anthracene oil (a coal tar distillate containing 1 percent nitrogen and 0.65 percent sulfur) instead of slurry oil. The hydrogen absorption using the catalyst with arsenic was 34 percent higher than with the catalyst containing iron only.

EXAMPLE 4 A catalyst was prepared from a Y-type molecular sieve as in Example 1 by treating 50 grams of the arsenic pentoxide-impregnated ammonium Y zeolite with a solution of 15 grams of zinc nitrate in 200 ml. water at 90C. for 4 hours, and then filtering, drying and heattreating at 400C. for 2 hours.

Using this catalyst for hydrogenation of anthracene oil at 430C. temperature, an amount of hydrogen uptake equivalent to 3,300 p.s.i.g. was observed. When using a similar catalyst containing zinc, but without the arsenic, the hydrogen uptake measured was only 1,100 p.s.i.g. Another significant advantage for the arsenic containing catalyst in this instance is that it resulted in a product having less than 0.02 percent nitrogen whereas the run with the arsenic free catalyst gave a product having 0.30 percent nitrogen.

EXAMPLE 5 Using a catalyst of a Y-type molecular sieve prepared as in Example 2 but containing cobalt instead of iron, hydrogenation of anthracene oil was carried out to give 14 percent by volume of a liquid product distilling below 430F. The liquid product distilling above 430C. contained 0.20 percent sulfur and 0.10 percent nitrogen. When the hydrogenation was repeated using a similar cobalt Y zeolite catalyst free of arsenic, slightly more hydrogen was absorbed, but the liquid product distilling above 430F. contained 0.27 percent sulfur and 0.22 percent nitrogen.

It is clear from the above examples of the invention that the Y-type zeolite containing arsenic is an effective catalyst for hydrogenation. It is also significant that combinations of arsenic with iron result in increased hydrogenation activity, and combination of arsenic with zinc or cobalt result in significant nitrogen removal from the petroleum oil hydrogenated.

The invention claimed is:

l. A hydrogenating process for a mineral oil fraction boiling above about 300F. whereby nitrogen content of the oil is reduced, which comprises contacting said fraction with hydrogen under hydrogenation conditions and in the presence of a catalyst composition consisting essentially of a Y-type zeolite having associated therewith from 1 percent to 15 percent by weight of arsenic and from 1 to 15 percent by weight of cobalt or zinc.

2. The process of claim 1 where the catalyst contains of from 5 to 10 percent arsenic and from 3 to 7 percent cobalt.

3. The process of claim 1 where the catalyst contains ofS to 10 percent arsenic and 3 to 7 percent zinc. 

2. The process of claim 1 where the catalyst contains of from 5 to 10 percent arsenic and from 3 to 7 percent cobalt.
 3. The process of claim 1 where the catalyst contains of 5 to 10 percent arsenic and 3 to 7 percent zinc. 